A Hub Enclosure for a Hub of a Wind Turbine

ABSTRACT

A hub enclosure ( 6 ), e.g. a spinner, for a hub ( 4 ) of a wind turbine is disclosed. The hub enclosure ( 6 ) comprises an aperture defining an aperture area and at least two aperture covers ( 10 ). The aperture covers ( 10 ) are arranged to cover substantially separate parts of the aperture area. Each of the aperture covers ( 10 ) is movable between a first position and a second position. In the first position the corresponding part of the aperture area is closed, and in the second position the corresponding part of the aperture area is open. The aperture covers ( 10 ) are positioned relative to each other in such a manner that neighbouring aperture covers ( 10 ) are arranged to cover adjacent parts of the aperture area. Thus, when two neighbouring aperture covers ( 10 ) are both in the second position, an opening is defined having an area which corresponds to the sum of the areas covered by the two aperture covers ( 10 ). Thereby a passage opening of a desired size can be obtained, simply be moving an appropriate number of neighbouring aperture covers ( 10 ) to the second position. This allows objects of various size to pass through the aperture without compromising the strength of the structure.

FIELD OF THE INVENTION

The present invention relates to a hub enclosure for a hub of a windturbine. The hub enclosure may be a spinner or it may be a part which ismounted directly on a hub of a wind turbine. More particularly, thepresent invention relates to a hub enclosure being provided with anaccess aperture with an adjustable size.

BACKGROUND OF THE INVENTION

It is sometimes required to provide a possibility of gaining access toan interior part of a hub of a wind turbine, e.g. to a spinner part or anose cone part. It may, e.g., be necessary to gain access to theinterior part of the hub in order to install, remove or replacecomponents of the wind turbine, e.g. generator, gear, etc. In this caseit is necessary to provide access openings of an appropriate size andshape to allow such components to pass. Alternatively or additionally,the access openings may be of a size and shape which allows a person topass, e.g. in order to allow maintenance personnel to enter the area ofthe hub, and/or in order to provide an emergency exit from the nacelle.

Furthermore, it may be desirable to provide openings in a region nearthe hub for the purpose of providing ventilation. US 2006/0120862discloses a wind energy plant with an aeration equipment for a rotorhub. The aeration equipment has a cup-shaped element which has a bottomand a circumferential side wall, and a pipe-shaped connection piece,directed into an inner space of the rotor hub. The cup-shaped element iskept in front of an entrance opening of the connection piece such thatthe entrance opening is arranged in the interior of the cup-shapedelement. The openings disclosed in US 2006/0120862 are very inflexible,and they are not suitable for allowing large components of a windturbine or persons to pass.

DESCRIPTION OF THE INVENTION

It is an object of embodiments of the invention to provide a hubenclosure which is adapted to allow objects of various sizes to passbetween the interior and the exterior of the hub enclosure.

It is a further object of embodiments of the invention to provide a hubenclosure which is adapted to allow large objects to pass between theinterior and the exterior of the hub enclosure without compromising thestrength of the structure.

It is an even further object of embodiments of the invention to providea hub enclosure with access openings of configurable size and shape.

The invention provides a hub enclosure for a hub of a wind turbine, saidhub enclosure comprising:

-   -   an aperture defining an aperture area,    -   at least two aperture covers arranged to cover substantially        separate parts of the aperture area, each of the aperture covers        being movable between a first position in which the        corresponding part of the aperture area is closed and a second        position in which the corresponding part of the aperture area is        open,        wherein the aperture covers are positioned relative to each        other in such a manner that neighbouring aperture covers are        arranged to cover adjacent parts of the aperture area.

In the present context the term ‘hub enclosure’ should be interpreted tomean a part of the wind turbine which partly or entirely encloses orcovers the hub. The hub enclosure may, e.g., be a spinner, a nose coneor a part of a spinner or a nose cone. Alternatively, it may be a partwhich is mounted directly on the hub.

The aperture defines an aperture area. The aperture area is preferably amaximum size of the aperture, defining the maximum size of componentsallowed to pass between the interior of the hub enclosure and theexterior of the hub enclosure.

The hub enclosure comprises at least two aperture covers. The aperturecovers are arranged to cover substantially separate parts of theaperture area. This should be interpreted to mean that the aperturecovers do not overlap, or that there is only a small overlap betweenneighbouring aperture covers. Furthermore, the aperture covers incombination cover the entire aperture.

Each of the aperture covers is movable between a first position and asecond position. When an aperture cover is in the first position thecorresponding part of the aperture is closed, and when an aperture coveris in the second position the corresponding part of the aperture isopen. Thus, when all of the aperture covers are in the first positionthe entire aperture is closed, and passage between the interior of thehub enclosure and the exterior of the hub enclosure is not possible.When all of the aperture covers are in the second position the entireaperture is open, thereby allowing passage of objects of a maximum sizebetween the interior of the hub enclosure and the exterior of the hubenclosure. Finally, when some of the aperture covers are in the firstposition and some of the aperture covers are in the second position, theaperture is partly open and partly closed, thereby defining an accessopening which is smaller than the aperture area. The size of the accessopening corresponds to the combined area of the aperture covers whichare in the second position.

The aperture covers are positioned relative to each other in such amanner that neighbouring aperture covers are arranged to cover adjacentparts of the aperture area. Thus, when two neighbouring aperture coversare both in the second position an access opening is defined which hasan area corresponding to the sum of the areas covered by the twoaperture covers. Accordingly, an opening of a specific size in order toallow a specific object to pass between the interior of the hubenclosure and the exterior of the hub enclosure can be provided, simplyby moving a sufficient number of neighbouring aperture covers to thesecond position, thereby obtaining a passage of a sufficient area.Thereby the size of the aperture can easily be configured or adjusted tomatch the requirements of the present situation.

It should be noted that the hub enclosure may be provided withadditional apertures, each defining an aperture area, and each having atleast two associated aperture covers as described above.

Each of the aperture covers may be movable from the first position tothe second position in a direction towards an interior part of the hubenclosure. In the case that an aperture is moved outwards there is arisk that a gust catches the aperture cover, thereby causing damage tothe aperture cover, or even tearing the aperture cover off, therebyrisking that it falls to the ground causing damage to buildings orstructures on the ground, or injuries or even fatalities to personslocated in the vicinity of the wind turbine. It is therefore anadvantage to design the aperture covers to be movable from the firstposition to the second position in a direction towards an interior partof the hub enclosure. However, embodiments could be envisaged in whichone or more of the aperture covers are movable from the first positionto the second position in an outwards direction.

Each of the aperture covers may be hinged to a part of the hubenclosure. According to this embodiment the aperture covers are movedpivotally between the first position and the second position via ahinge. Hinging the aperture covers to the hub enclosure is a simple wayof mounting the aperture covers in a movable manner. As an alternative,one or more of the aperture covers may follow alternative movingpatterns, e.g. a sliding moving pattern.

The aperture may be arranged in a tip part of the hub enclosure,preferably covering the entire tip part. In the present context the term‘tip part’ should be interpreted to mean an outermost part of the hubenclosure, arranged as far as possible from the nacelle. As analternative, the aperture may be arranged closer to the nacelle.

The hub enclosure may further comprise a sealing element arranged tocover a part of at least two of the aperture covers. The sealing elementprovides sealing between neighbouring aperture covers, and it canthereby be ensured that the hub enclosure is substantially tight whenall of the aperture covers are in the first position.

The sealing element may be arranged to cover a part of each of theaperture covers, or it may be arranged to cover a part of only some ofthe aperture covers. In the case that the aperture is arranged in a tippart of the hub enclosure the sealing element may advantageously bearranged at the outermost part of the tip, preferably in a region whereall of the aperture covers meet. In such a region there is a high riskthat leaks occur, and it is therefore an advantage to position a sealingelement there. Alternatively or additionally, one or more sealingelements may be arranged in regions where two neighbouring aperturecovers meet, and/or in regions defining an interface between theaperture and other parts of the hub enclosure.

As mentioned above the hub enclosure may be or form part of a spinner.As an alternative, it may be or form part of a nose cone. As anotheralternative, it may be a part which is mounted directly on the hub.

Each of the aperture covers may be manually movable between the firstposition and the second position. According to this embodiment theaperture covers are always movable, regardless of power failures, fire,breakdown, etc. Furthermore, manually movable aperture covers areadvantageous in the case that the aperture is to be used as an emergencyexit from the nacelle.

Alternatively or additionally, the hub enclosure may further comprisemeans for automatically moving each of the aperture covers between thefirst position and the second position. Automatic movement of theaperture covers allows them to be moved without requiring the presenceof a person at the hub enclosure. It may be advantageous to be able tomove the aperture covers automatically as well as manually. In this casethe aperture covers may be moved automatically under normalcircumstances, and the aperture covers may be manually movable in thecase of an emergency.

Each of the aperture covers may be mounted detachably on the hubenclosure. According to this embodiment it may be possible to completelyremove the aperture covers, thereby providing improved clearance forpassage of objects through the aperture. Furthermore, the risk ofdamaging the aperture covers during movement of large and heavycomponents through the aperture is reduced.

The hub enclosure of the present invention may advantageously bepositioned at the hub of a wind turbine. Accordingly, the presentinvention further relates to a wind turbine comprising a hub enclosureaccording to the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in further detail with reference tothe accompanying drawings in which

FIG. 1 is a schematic illustration of a nacelle of a wind turbine,

FIG. 2 is a side view of a hub enclosure according to an embodiment ofthe invention, the hub enclosure being mounted on a hub,

FIG. 3 is a front view of a hub enclosure according to an embodiment ofthe invention,

FIG. 4 is a perspective view of the hub enclosure of FIG. 3 as seen frominside the hub enclosure,

FIG. 5 shows the hub enclosure of FIGS. 3 and 4 from a different angle,

FIG. 6 is a perspective view of the hub enclosure of FIGS. 3-5 with oneaperture cover open,

FIG. 7 is a perspective view of the hub enclosure of FIGS. 3-6 with twoaperture covers open,

FIG. 8 is a perspective view of the hub enclosure of FIGS. 3-7 with oneaperture cover removed,

FIG. 9 shows an aperture cover of the hub enclosure of FIGS. 3-8, and

FIG. 10 is a detail of FIG. 9.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration of a nacelle 1 of a wind turbine.Inside the nacelle 1 a gear system 2 and a generator 3 are arranged. Ahub 4 holding a set of turbine blades 5 is coupled to the gear system 2.A hub enclosure 6 is mounted at a tip end of the hub 4. Accordingly,FIG. 1 illustrates a possible position of a hub enclosure 6 according tothe invention.

FIG. 2 is a side view of a hub enclosure 6 according to an embodiment ofthe invention. The hub enclosure 6 is mounted on a hub 4 which isprovided with mounting portions 7 adapted to have turbine blades mountedthereon.

The hub enclosure 6 comprises an inner part 8 and an outer part 9. Theinner part 8 is arranged closer to the hub 4 than the outer part 9. Theinner part 8 forms a substantially single part which extends the entireperimeter of the hub enclosure 6. The outer part 9 is formed by threemovable covers. This will be explained in further detail below.

FIG. 3 is a front view of the hub enclosure 6 of FIG. 2. In FIG. 3 thehub enclosure 6 is seen from the exterior of the hub enclosure 6. It isclear from FIG. 3 that the outer part 9 of the hub enclosure 6 comprisesthree substantially identical aperture covers 10, separated by mountingparts 11. Each of the aperture covers 10 is releasably attached to eachof its adjacent mounting parts 11 by means of fittings 12. The mountingparts 11 provide sealing between the aperture covers 10. Each aperturecover 10 is further hinged to the inner part 8 of the hub enclosure 6 bymeans of a hinge 13. Thus, a part of the aperture can be opened byreleasing the fittings 12 corresponding to the aperture cover 10covering the part of the aperture and rotating the aperture cover 10 viathe hinge 13. This will be described further below.

A cover plate 14 is arranged at a centre part of the tip of the hubenclosure 6. Since the three aperture covers 10 as well as the threemounting parts 11 meet at the tip, there is a risk that leaks may occurin this region. The cover plate 14 provides sealing to the region,thereby reducing, or even preventing, leaks.

FIG. 4 is a perspective view of the hub enclosure 6 of FIGS. 2 and 3,seen from an interior part of the hub enclosure 6. In FIG. 4 thefittings 12 and the hinges 13 are clearly seen. It is also clear thatthe hinges 13 are arranged in such a manner that the aperture covers 10are moved inwards, i.e. towards an interior part of the hub enclosure 6,when rotated via the hinges 13.

Each of the aperture covers 10 is provided with two handles 15. When anaperture part is opened manually a person can grip the handles 15 of acorresponding aperture cover 10, after having released the fittings 12,and thereby rotate the aperture cover 10 manually via the hinge 13.

FIG. 5 shows the hub enclosure 6 of FIG. 4 from a slightly differentangle.

FIG. 6 is a perspective view of the hub enclosure 6 of FIGS. 2-5 seenfrom an interior part of the hub enclosure 6. In FIG. 6 one of theaperture covers 10 has been moved via the hinge 13, thereby providing anaperture part having an area corresponding to the area of the aperturecover 10 and allowing access between an interior part of the hubenclosure 6 and the exterior of the hub enclosure 6. It can be seen thatthe fittings 12 of the aperture cover 10 has been released, and that theaperture cover 10 has been moved inwards via the hinge 13. The inwardsmovement of the aperture cover 10 ensures that the aperture cover 10 isunder control during this movement, and the risk of dropping theaperture cover 10 out of the hub enclosure 6 is minimised.

FIG. 7 is a perspective view of the hub enclosure 6 of FIGS. 2-6 seenfrom an interior part of the hub enclosure 6. In FIG. 7 two neighbouringaperture covers 10 have been moved via the corresponding hinges 13.Furthermore the mounting part which is normally arranged between the twomoved aperture covers 10 has been removed. As a consequence one largeaperture has been provided, the aperture having an area corresponding tothe combined areas of the two moved aperture covers 10. It is therebyclear from FIG. 7 that the hub enclosure 6 of FIGS. 2-7 provides thepossibility of customizing the area of the aperture to match therequirements of a given task. Thus, if only a small component is to bepassed through the aperture, only one aperture cover 10 is moved. If asomewhat larger component or a person is to be passed through theaperture, two or three aperture covers 10 are moved, thereby providingan aperture having an area which is two or three times as large as anaperture obtained by moving only one aperture cover 10.

FIG. 8 is a perspective view of the hub enclosure 6 of FIGS. 2-7 seenfrom an interior part of the hub enclosure 6. In FIG. 8 one aperturecover 10 has been moved as described above with reference to FIG. 6.Subsequently, this aperture cover 10 has been removed by releasing itfrom the hub enclosure 6 at the hinge 13, e.g. by releasing one or morescrews or other suitable fastening means. Removing the aperture cover 10in this manner ensures a more free passage for components or personsthrough the aperture. This may be required in some cases, and it istherefore an advantage that it is possible to remove an aperture cover10 completely.

FIG. 9 shows an aperture cover 10 of the hub enclosure 6 of FIGS. 2-8.It can be seen that each of the fittings 12 comprises a manually movablepawl 16, each engaging a hole formed on the corresponding mounting part11. Thus, when it is desired to open a part of the aperture, an operatorcan pull back the pawls 16 of the relevant fittings 12 until they nolonger engage the holes of the mounting parts 11, thereby releasing therelevant aperture cover 10 from the adjacent mounting parts 11.Subsequently, the aperture cover 10 can be moved inwards via the hinge13 by pulling the handles 15.

FIG. 10 is a detail of FIG. 9 showing the fittings 12. In FIG. 10 it canbe seen how the pawls 16 of the fittings 12 engage holes 17 formed onthe mounting part 11, thereby locking the aperture covers to themounting part 11.

1-10. (canceled)
 11. A hub enclosure for a hub of a wind turbine, saidhub enclosure comprising: an aperture defining an aperture area; and atleast two aperture covers arranged to cover substantially separate partsof the aperture area, each of the aperture covers being movable betweena first position in which the corresponding part of the aperture area isclosed and a second position in which the corresponding part of theaperture area is open; wherein the aperture covers are positionedrelative to each other in such a manner that neighbouring aperturecovers are arranged to cover adjacent parts of the aperture area, andwherein each of the aperture covers is movable from the first positionto the second position in a direction towards an interior part of thehub enclosure.
 12. The hub enclosure according to claim 11, wherein eachof the aperture covers is hinged to a part of the hub enclosure.
 13. Thehub enclosure according to claim 11, wherein the aperture is arranged ina tip part of the hub enclosure.
 14. The hub enclosure according toclaim 11, further comprising a sealing element arranged to cover a partof at least two of the aperture covers.
 15. The hub enclosure accordingto claim 11, wherein the hub enclosure is or forms part of a spinner.16. The hub enclosure according to claim 11, wherein each of theaperture covers is manually movable between the first position and thesecond position.
 17. The hub enclosure according to claim 11, furthercomprising means for automatically moving each of the aperture coversbetween the first position and the second position.
 18. The hubenclosure according to claim 11, wherein each of the aperture covers ismounted detachably on the hub enclosure.
 19. A wind turbine comprising ahub enclosure according to claim 11.